If you have recently re-attached your content database to the new web application in SharePoint 2007 (whether because you have moved your SharePoint install or simply because you had to re-create the web application on your current server), you might have noticed a new error (Event ID: 5555; Event Source: Office SharePoint Server) occurring hourly in the Event Log of your web-front SharePoint server.
The description of the error tells you to run stsadm – o preparetomove, which doesn't seem to fix the problem, unfortunately. This command only prevents the error 5555, if you run it before moving and re-attaching your content databases. To fix error 5555, you need to run stsadm –o sync instead.
In my case, running the following command made error 5555 disappear:
stsadm -o sync -DeleteOldDatabases 0
As usual: ALWAYS BACKUP YOUR SHAREPOINT BEFORE MAKING ANY CHANGES TO ITS CONFIGURATION